Cleaning device for pulverized fuel furnaces



July 12,1932. R, RQQSEN 1,867,101

CLEANING DEVICE FOR PULVERIZED FUEL FURNACES Filed Aug. 13, 1930 2Sheets-Sheet 1 July 12, 1932. R. ROOSEN CLEANING DEVICE FOR PULVERIZEDFUEL FURNACES Filed Aug. 13, 1950 2 Sheets-Sheet 2 3 w mvkw fiz'cardRama:

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Patented July 12, 1932 UNrren HE Pram" FFICE RICHARD ROOSEN, F KASSEL,GERMAN Y, ASSIGNOR EEO STUG KOHLENSTAUBFEUERUTTG V PATENTVERW'ERTUNG- G.IVIQ B. B1, OF KASSEL, GERMANY CLEANING DEVICE FOR PULVERIZED FUELFURNACES Application filed August 13, 1930, Serial No. 475,069, and inGermany November 13, 1929.

on the walls of the combustion chamber.

The new device comprises a movable combined blast pipe mounted in a ballhead on the wall of the combustion. chamber which blast pipe is composedof an inner pipe and a concentrically arranged outer pipe, the

former serving to project sand at high speed against the walls of thecombustion chamber by means of compressed air, while high pressure steamis projected by the latter pipe.

The use of steam-sand blasts for cleaning purposes of this kind is knownin itself; the older designs, however, suffer from several fundamentaldrawbacks. In the first place these known devices are applied in a veryprimitive manner by simply inserting the device in or mounting it on,acorresponding aperture in the wall of the combustion chamber. This modeof application is not satisfactory if steam of high pressure is used. Incontra-distinction thereto, the provision of a ball head in which thedevice is mounted ac cording to the invention, enables perfecttightening of the members that feed the steam. Furthermore, in theseolder designs the steam is supplied through the inner pipe while sand isfed through the outer one.

spreading of the sand takes place, so that the whole jet enlarges to aninadmissible eX- tent on its way up to the impact place on the wall,whereby the cleaning effect is seriously derogated. By the inversearrangement, however, as practiced by the invention, that is by thesteam jet enveloping the sand jet, the advantage is obtained that thelatter arrives at the wall in a uniformly closed condition, whereby amuch better cleaning effect is obtained, more particularly in removingthe very hard honey combs. Finally, by the steam jacket surrounding thesand jet both the drying of the sand that happens to have become moistand which would easily adhere to the walls of the combustion chamber isobtained, as well as the heating of the cold sand-conveylng air betweenthe sand box and thus the steam jet is within the sand jet, I

the blast pipe, whereby injuries of the boiler,-

caused by its being struck by cold air, are avo ded.

In order that the invention can be more readily understood, anembodiment of the same isillustrated by way of example in theaccompanying drawlngs 1n whlch Figure 1 is a longitudinal sectionthrough the rear part of a locomotive boiler with the blast device,

Figure 2 is a longitudinal section through the blast device andthe meansby which it is fixed to the wall of the combustion chamber, on anenlarged scale, and v Fig. 3 is a plan View of a modified constructionalembodiment of my invention.

Referring to Figs. 1 and 2, a denotes the combustion chamber in front ofan aperture 6 of which is mounted the blast device 0.

Sand is fed to this device from the box d by means of apipe e whieh'isflexible in part. The air under pressure required to convey the sandthrough pipe 6 is supplied through a pipe 7" from the main air tank(notshown). Steam is supplied-through a pipe 9 from the dome, nothrottling member being interposed but a valve it serving to shut offpipe G. The latter opens into a tubular casing 70, Figure 2, which atthe pointof entrance of pipe 9 externally forms a ball head and isclosed on its rear end Zby a screw plug m that hasfa bore a. Into thisbore opens from outside the sandsupply pipe 6 while on the side turnedtothe ball head '5 the bore a is prolonged by a pipe 0 which extendsabout up to the end of the tubularcasing 7c. The ball head 2' rests in acorrespondingly shaped outer casing 79 which is mounted on the seating gof the hole. The outer casing p is fitted with'a drain cock 1'' and thetubular casing k is fitted on its outer end with a handie 5 so that theblast device canbe turned to all sides, in order to sweep the entiretube wall t of the boiler.

.Vhen the described appliance is inoperation, the steam escaping fromthe tubular casing 76 envelopes'the sand thrown out by the pipe 0. Thesand thus arrives in a closed jet at the place to be cleaned oft-hewall'and at the same time is preheated by the surthat opens into anotherball head situated in rounding steam and, if moist, dried. Thesand-conveying air is likewise dried so that it cannot meet the wall incold state and injure it. I

The constructional details of the device forming the subject-matter ofthe invention may be modified in many respects. So, for instance, thedevice can be mounted on a hinged fire door by making the socket for theball head. i'integral with the door itself which in its turn includes asteam channel the pivot axis of the door and embracing the hinge boltthereof, the steam pipe that comes from the dome opening into this ballhead- Furthermore, the sand duct which is described as flexible in part,may be replaced by a rigid duct including ball joints on the placeswhere turning motion is required. The above construction is bestillustrated by reference to Fig. 3, wherein the modified blowing deviceis movably arranged in the middle of fire door 'w. The door it is rotat-V ably mounted by its hinge a in hinge elements w fixed upon the rearboiler wall '2).

The taps m, w", set in hinge a are hollow. The tap w is connected uponone end thereof through a ball or similarly rotatable joint 3 to a pipe9 which leads to the steam dome for the supply of steam (not shown). Theother end of the tap communicates through pipe 9 with that portion of cwhich corresponds to the steam nozzle is in Fig. 2. The other tap m islikewise connected at one end thereof through rotatable oint z to pipe6" which leads to supply container for the sand (not shown) The otherend of the tap is connected through pipe 6 with that portion of 0 whichcommunicates with tube 0, in Fig. 2. By this construction it is possibleto close and open the firedoor without affecting the conducting tubes g,g", e, e and the cleaning device 0.

I'claim: Y

. 1. A cleaning device for pulverized fuel furnaces comprising a steamnozzle mounted by means of a ball joint in front of and projecting intoa hole in the fire door of the furnace, another nozzle concentricallyarranged within said steam nozzle, means for supplying sand underpressure to said other nozzle, a duct for feeding steam to said steamnozzle through said ball joint and comprising-another ball jointsituated in the pivot axis of said fire door, and pipe connections fromthe source of steam to said last-named ball joint and from the latter tosaid firstnamed ball oint.

2. A cleaning device for pulverized fuel furnaces comprising a steamnozzle mounted by means of a ball joint in front of and projecting intoa hole in the fire door of the furnace, another nozzle concentricallyarranged within said steam nozzle, ducts for feeding, respectively,steam and sand under

